<script>
  let a = [1, 2, 3];
  console.log(typeof a);
  console.log(a instanceof Array);
  let obj = { a: 1 };
  console.log(typeof obj);

  console.log("---------------");
  let str = "aaa";
  console.log(typeof str);
  let num = 123;
  console.log(typeof num);
  let flag = false;
  console.log(typeof flag);
  let symbol = Symbol(1);
  console.log(typeof symbol);
  console.log(typeof console.log);
</script>
